Versatile Chlorin e6-based magnetic polydopamine nanoparticles for effectively capturing and killing MRSA

Bacterial infections are a growing global challenge for public health as antibiotic resistance could cause the failure of anti-infective treatment eventually. So, it is urgent to develop new potential antibacterial materials. Herein, a multifunctional chitosan (CS) functionalized magnetic Chlorin e6 (CS-MP-Ce6) was constructed to combat methicillin-resistant Staphylococcus aureus (MRSA) infection by integrating bacterial conjugation and enrichment, and near-infrared (NIR)-triggered photodynamic sterilization. CS-MP-Ce6 could efficiently capture bacteria due to positively charged property of CS, and Ce6 acted as an effective photodynamic killer to convert NIR light into local energy to enhance antibacterial activity. Specifically, after being trapped together with MRSA, CS-MP-Ce6 showed an excellent in vitro photodynamic sterilization ability. In vivo MRSA-induced abscess treatment studies showed faster healing when CS-MP-Ce6 was used as subcutaneous nano-localized energy sources with the assistance of external magnet to concentrate CS-MP-Ce6-bacteria conjugate. This work provides a promising framework for constructing a new system for efficiently combating MRSA.